Hello and welcome! My name is Doris.I have been an antiques collector, dealer and appraiser for over 56 years.I will be pleased to help you.
I can tell you if the drawing is similar in style and signature to Delacroix. I can tell you if there are any reproduction prints of the drawing available. You sound as though you are a very knowledgeable collector; so, you may already know this information.
Unfortunately, authoritative identification of art cannot not be done via a photo. To authenticate art, the piece must be examined in person. If you tell me where you live, I can probably locate an appraiser within driving distance of your location.
If you wish, please send the following:
Please send a photo of the signature. Please also send a photo of the drawing.
You may need to use the macro function (flower icon) of your camera to get a good clear photo of the signature.
To send photos you may use the "reply to expert" or "add files" in the blue box link on your reply page or the "paper clip" found in the toolbar you see on your reply page.Please do not send in ZIP format. The jpg or jpeg format works best.
An explanation of this method can be found here: